The neurogenic bladder caused by spinal cord injury presents a significant medical and social problem. Aside from the poor quality of life because of the uncontrollable bladder, two thirds of the victims will die of the chronic urinary infections and renal failure. There is no satisfactory treatment. The research proposed here is to try to restore the controllable micturition by establishing a new reflex pathway "Skin-CNS-Bladder" in the canine model. The venture root(VR) of a lumbar nerve(L7) will be anastomosed extradurally to the sacral VR(s) which innervate the bladder, while leaving the intact L7 dorsal root(DR) as a starter of micturition. After the axonal regeneration, controllable voiding would be initiated by stimulation of the L7 nerve which should have only sensory functions (by scratching the L7 related skin in the patients). The new pathway will be tested by using techniques of horseradish peroxidase (HRP) neural tracing and electrophysiology. Bladder urodynamics and external urethral sphincter EMG will be examined to evaluate the function. Possible ultramicro-structural changes following the somatic axon regeneration in preganglionic synaptic terminals, pelvic ganglionic neurons and bladder detrusor muscle will be examined at light and/or electron microscopic level. The "Skin-CNS-Bladder" pathway may greatly improve the treatment of the neurogenic bladder. It is interesting and theoretically important to clarify if and how somatic axons can regenerate into an autonomic nerve and reinnervate the effector, and how the two nervous systems co-operate in the "Skin-CNS-Bladder" reflex. This may result in a new concept and lead to a new research field in neuroscience. The new concept, i.e. the impulses delivered from the efferent neurons of a somatic arc may be transferred to initiate response of an autonomic effector, may be widely useful, not only for neurogenic bladder, but also for other problems caused by the spinal cord injury or diseases.